import AppIntents
import WidgetKit

// ──────────────────────────────────────────────────────────────────────
// WidgetIntents.swift
// TARGET: Widget extension only.
//
// iOS 17+ interactive widget controls via AppIntents.
// Each intent writes a command to App Group UserDefaults, optimistically
// updates the widget state, posts a Darwin notification to wake the app,
// then reloads timelines so the widget re-renders immediately.
// ──────────────────────────────────────────────────────────────────────

// MARK: - Play / Pause

struct PlayPauseIntent: AppIntent {
    static var title: LocalizedStringResource = "Toggle Playback"
    static var description: IntentDescription = "Play or pause the current track."

    func perform() async throws -> some IntentResult {
        let state = WidgetSharedState.shared
        // Optimistic toggle — widget re-renders with new state instantly
        state.togglePlayingOptimistic()
        // Enqueue command for the main app
        let wasPlaying = !state.isPlaying  // we already toggled
        state.enqueueCommand(wasPlaying ? .pause : .play)
        postDarwinNotification(kWidgetCommandNotification)
        WidgetCenter.shared.reloadAllTimelines()
        return .result()
    }
}

// MARK: - Next Track

struct NextTrackIntent: AppIntent {
    static var title: LocalizedStringResource = "Next Track"
    static var description: IntentDescription = "Skip to the next track."

    func perform() async throws -> some IntentResult {
        let state = WidgetSharedState.shared
        state.enqueueCommand(.next)
        postDarwinNotification(kWidgetCommandNotification)
        WidgetCenter.shared.reloadAllTimelines()
        return .result()
    }
}

// MARK: - Previous Track

struct PreviousTrackIntent: AppIntent {
    static var title: LocalizedStringResource = "Previous Track"
    static var description: IntentDescription = "Go to the previous track."

    func perform() async throws -> some IntentResult {
        let state = WidgetSharedState.shared
        state.enqueueCommand(.previous)
        postDarwinNotification(kWidgetCommandNotification)
        WidgetCenter.shared.reloadAllTimelines()
        return .result()
    }
}

// MARK: - Seek Forward (+15s)

struct SeekForwardIntent: AppIntent {
    static var title: LocalizedStringResource = "Seek Forward"
    static var description: IntentDescription = "Skip forward 15 seconds."

    func perform() async throws -> some IntentResult {
        let state = WidgetSharedState.shared
        state.enqueueCommand(.seekForward15)
        postDarwinNotification(kWidgetCommandNotification)
        WidgetCenter.shared.reloadAllTimelines()
        return .result()
    }
}

// MARK: - Seek Backward (-15s)

struct SeekBackwardIntent: AppIntent {
    static var title: LocalizedStringResource = "Seek Backward"
    static var description: IntentDescription = "Skip backward 15 seconds."

    func perform() async throws -> some IntentResult {
        let state = WidgetSharedState.shared
        state.enqueueCommand(.seekBackward15)
        postDarwinNotification(kWidgetCommandNotification)
        WidgetCenter.shared.reloadAllTimelines()
        return .result()
    }
}

// MARK: - Seek To Position (tap-to-seek on progress bar)

struct SeekToIntent: AppIntent {
    static var title: LocalizedStringResource = "Seek To Position"
    static var description: IntentDescription = "Seek to a specific position in the track."

    @Parameter(title: "Fraction")
    var fraction: Double

    init() { self.fraction = 0 }
    init(fraction: Double) { self.fraction = fraction }

    func perform() async throws -> some IntentResult {
        let state = WidgetSharedState.shared
        let targetTime = state.duration * min(max(fraction, 0), 1)
        state.enqueueSeekTo(time: targetTime)
        // Optimistically update position so widget shows new location instantly
        state.pushPosition(currentTime: targetTime, isPlaying: state.isPlaying)
        postDarwinNotification(kWidgetCommandNotification)
        WidgetCenter.shared.reloadAllTimelines()
        return .result()
    }
}